How do you approach IOL calculations and selection in patients with keratoconus based on disease severity?

Lens selection assuming stable KCN and no plan for a transplant:

1. Symmetrical astigmatism and they don't want to wear CL after surgery? Can consider a toric lens.
2. Symmetrical astigmatism and they are okay with continuing RGP/sclerals? Monofocal aberration-free lens.
3. Asymmetrical astigmatism and want...

I usually do these with the consultation of our cornea and contact lens colleagues.

Key question. What is the likelihood of PK? If no PK, are they planning to wear CL post op?

If they are likely getting PK after CE, then I get a reasonable K value post-transplant from our cornea service, or have the...

Formulas: I like using the Barrett True-K formula.

Lenses: I do not recommend multifocals or extended depth of focus. The keratoconus already induces optic aberrations, so placing those lenses might add to it.

If they are getting PK, I like to wait for the PK first, and we can do the cataract later....

If I have historical refractive information on the patient and refraction is stable, I would consider a toric lens. If in need of a PK, that first. Wait 5-6 months before cataract extraction. Otherwise monofical spherical lens.